NON-COVERED LOANS AND ALLOWANCE FOR LOAN LOSSES (Details 4) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014 item		Dec. 31, 2013
Credit Quality Indicators
Number of grades in the risk rating system utilized by the company to rate credit risk of loans receivable	8
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	$ 17,308,411	[1]	$ 15,678,317	[1]
Pass/Watch
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	16,546,361		14,991,479
Special Mention
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	236,093		197,284
Substandard
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	524,851		489,554
Doubtful
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	1,106
Residential
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	4,349,486		4,185,309
Residential | Residential Single-family
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	3,238,298		3,192,875
Residential | Residential Single-family | Pass/Watch
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	3,214,552		3,167,337
Residential | Residential Single-family | Special Mention
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	7,591		8,331
Residential | Residential Single-family | Substandard
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	16,155		17,207
Residential | Residential Multifamily
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	1,111,188		992,434
Residential | Residential Multifamily | Pass/Watch
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	1,048,621		923,697
Residential | Residential Multifamily | Special Mention
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	1,295		1,634
Residential | Residential Multifamily | Substandard
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	61,272		67,103
Commercial Real Estate ("CRE")
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	5,519,920		4,585,077
Commercial Real Estate ("CRE") | Income producing
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	5,118,377		4,301,030
Commercial Real Estate ("CRE") | Income producing | Pass/Watch
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	4,813,286		4,032,269
Commercial Real Estate ("CRE") | Income producing | Special Mention
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	81,582		56,752
Commercial Real Estate ("CRE") | Income producing | Substandard
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	223,509		212,009
Commercial Real Estate ("CRE") | Construction
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	197,628		140,186
Commercial Real Estate ("CRE") | Construction | Pass/Watch
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	184,580		127,138
Commercial Real Estate ("CRE") | Construction | Special Mention
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	6,160		6,160
Commercial Real Estate ("CRE") | Construction | Substandard
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	6,888		6,888
Commercial Real Estate ("CRE") | Land
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	203,915		143,861
Commercial Real Estate ("CRE") | Land | Pass/Watch
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	170,601		116,000
Commercial Real Estate ("CRE") | Land | Special Mention
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	6,298		9,304
Commercial Real Estate ("CRE") | Land | Substandard
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	27,016		18,557
Commercial and Industrial ("C&I")
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	6,201,083		5,360,193
Commercial and Industrial ("C&I") | Commercial Business
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	5,533,379		4,637,056
Commercial and Industrial ("C&I") | Commercial Business | Pass/Watch
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	5,264,264		4,400,847
Commercial and Industrial ("C&I") | Commercial Business | Special Mention
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	100,897		92,315
Commercial and Industrial ("C&I") | Commercial Business | Substandard
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	167,112		143,894
Commercial and Industrial ("C&I") | Commercial Business | Doubtful
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	1,106
Commercial and Industrial ("C&I") | Trade finance
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	667,704		723,137
Commercial and Industrial ("C&I") | Trade finance | Pass/Watch
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	617,185		681,345
Commercial and Industrial ("C&I") | Trade finance | Special Mention
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	31,775		22,099
Commercial and Industrial ("C&I") | Trade finance | Substandard
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	18,744		19,693
Consumer
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	1,237,922		1,547,738
Consumer | Student loans
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	184,900		679,220
Consumer | Student loans | Pass/Watch
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	183,062		677,094
Consumer | Student loans | Special Mention
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	148		445
Consumer | Student loans | Substandard
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	1,690		1,681
Consumer | Other Consumer
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	1,053,022		868,518
Consumer | Other Consumer | Pass/Watch
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	1,050,210		865,752
Consumer | Other Consumer | Special Mention
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	347		244
Consumer | Other Consumer | Substandard
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	$ 2,465		$ 2,522

[1] Loans net of ASC 310-30 discount